BEIJING, March 6 (Xinhuanet) -- Canadian researchers say ibuprofen is a more effective pain reliever than acetaminophen and codeine for children with musculoskeletal injuries to the extremities, neck and back. The study is published in the online edition of the journal Pediatrics Monday.

    The research team, led by Dr. Eric Clark of the Departments of Pediatrics and Emergency Medicine, University of Ottawa, recruited 336 children ages 6 to 17 who had been admitted to the emergency department of the Children's Hospital of Eastern Ontario in Ottawa.

    Of the 336 randomly assigned to be treated with oral doses of 15mg per kg of acetaminophen, 10 mg per kg of ibuprofen or 1 mg per kg of codeine, 300 were included in the analysis (100 in each drug group).

    The children in all three groups were similar by age, gender, the types of painkiller they had taken before, the final diagnosis of their injury and their pain levels at baseline time.

    The trial was designed to be double blind where neither the children's parents nor the researchers administering the drugs are told which drug group they are in.

    However in reality about half of them guessed which drug they were using, and this was acknowledged as a potential weakness in the trial, as was its small size and exclusion of many other available participants who would have met the random assignment criteria.

    The children were periodically asked to show how much pain they were feeling by placing a mark on a horizontal pain intensity scale from 0 to 100. This is known as a "visual analogue scale" and in this case it measured 100 mm wide.

    The main focus of the study was the pain intensity after 60 minutes from baseline, but the researchers also compared results after this time.

    The results showed that after 60 minutes, the children who had been given ibuprofen had the largest decrease in pain intensity. Their mean pain level decrease was 24 mm on the 100 mm scale, while the acetaminophen group showed a mean decrease of 12 mm and the codeine group 11 mm at the 60 minute point.

    The decrease in pain level of the three groups did not change at the 120 minute point.

    As well as showing the greatest mean decrease in pain level, the ibuprofen group also had more children at the below 30 mm level or the "adequate analgesia" level than the other two groups at 60 minutes.

    (Agencies)